As one of this kind of cooling storages, for example, Patent literature 1 as below has been disclosed, in which heat insulating freezing room and refrigeration room are partitioned in a heat insulation storage body, while an evaporator is provided in each room, so that a refrigerant is alternately supplied to each of these evaporators from one compressor to produce cooling action.
In this kind of refrigerator, a refrigerant is compressed by the compressor and then liquefied by the condenser, so as to be alternately supplied to the evaporator for freezing room and the evaporator for refrigeration room that are connected to the exit side of a three-way valve respectively via a capillary tube. At the time of so-called a control operation wherein a regular cooling operation is conducted within the temperature range close to a set temperature, for example, when the temperature in the cooling room reached the OFF temperature, the three-way valve is switched to the cooling mode for the other room, and then, the compressor is stopped when detected temperatures in both rooms reached the OFF temperature or below.
According to this configuration, in the above-mentioned control operation, when an user stores a food of high temperature in one storage room, this storage room is sufficiently cooled before the cooling is switched to the other storage room, and thus, it is advantageous that the newly stored food can be sufficiently cooled.
However, in the above configuration, when a food of high temperature is stored in both the storage rooms, there occurs a problem that the food in the storage room to be cooled on ahead would have no trouble, whereas the food in the other storage room to be cooled later would not be able to be cooled early enough.
In response to such a circumstance, for example, Patent Literature 2 has suggested an art in which a control device alternately switches both the storage rooms at a predetermined time ratio. Here, for example, when temperatures in both the storage rooms in the refrigeration room and the freezing room surpassed the ON temperature, an alternate cooling mode is executed for alternately switching the cooling between the freezing room and the refrigeration room at a ratio of for example 30:20 minutes. Furthermore, when the temperature in the freezing room still rises since the cooling performance is not sufficient, and when inside the freezing room reached a prescribed temperature (for example, −12 degrees), the above time ratio is changed to the one prioritizing the freezing room side (for example, 40:20 minutes), so as to suppress the rise of the temperature inside the freezing room.
[Patent Literature 1]: Japanese Unexamined Utility Model Publication No. S60-188982
[Patent Literature 2]: Japanese Unexamined Patent Publication No. 2002-22336
However, even with the above configuration, the cooling is immediately switched to the alternate cooling mode, when, for example, the cooling mode was switched to the freezing room cooling mode since a food of high temperature was stored in the freezing room and caused the temperature inside the room to rise above the ON temperature, and after that, this time, the door of the refrigeration room is opened and closed frequently, causing the temperature inside the room to rise above the ON temperature even temporarily. This delays the cooling of the freezing room since apart of the cooling performance is spared for cooling the refrigeration room, and eventually, the temperature rise within the freezing room cannot be sufficiently suppressed.
And also, when conducting so-called a pull-down operation, not a normal control operation, for cooling the storage room temperature from the one close to the room temperature down to around a set temperature, and when the alternate cooling mode is performed at the above long cycle of 30:20 minutes, the cooling operation of the storage room temperature at a predetermined temperature curve cannot be conducted, and thus, there occurs variations in the cooling performance according to specifications such as the volume of the storage body. But then again, if the switching in the alternate cooling mode is conducted at a short cycle such as, for example, 3:2 minutes, the problem of sparing the cooling performance for the refrigeration room becomes unfavorably prominent even when a quick cooling of the freezing room as mentioned above is required.
The present invention has been completed based on the above circumstances, and its purpose is to provide a cooling storage and an operating method of the same, in which from one compressor a refrigerant is selectively supplied to multiple evaporators respectively disposed in multiple storage rooms of varied thermal loads, and is capable of preventing a one-storage room cooling mode to be unnecessarily switched to the alternate cooling mode, and moreover, of executing a pull-down operation at a predetermined temperature curve.